Nowadays, “Inter-band CA (Carrier Aggregation)” is studied in the meetings for developing LTE (Long Term Evolution) specifications.
As shown in FIG. 21, a conventional radio configuration for implementing “Inter-band CA” includes a duplexer #A for switching transmission and reception in a band #A, a duplexer #B for switching transmission and reception in a band #B, and a diplexer in which the duplexer #A and the duplexer #B are housed.